Once daily administration of irbesartan 75 mg for 4 weeks, titrated to 150 mg for an additional 4 weeks and further titrated to 300 mg for an additional 6 weeks to hypertensive subjects with Type II diabetes mellitus and proteinuria (24-hour urine protein excretion > 1000 mg) will be safe and well-tolerated, and will not adversely affect serum creatinine when compared to treatment with a calcium channel antagonist. Once daily administration of irbesartan 75 mg for 4 weeks, titrated to 150 mg for an additional 4 weeks, and further titrated to 300 mg for an additional 6 weeks, to hypertensive subjects with Type II diabetes mellitus and proteinuria will produce a reduction in urine protein and albumin excretion.